3.3.16.6 Record: DataItem

Topic Version1Published10/31/2016
For StandardETP v1.1

A single data point on a channel is the data record used in the Streaming protocol.

Avro Schema

{

      "type": "record",

      "namespace": "Energistics.Datatypes.ChannelData",

      "name": "DataItem",

      "fields":

     [

         {

          "name": "indexes",

          "type": { "type": "array", "items": "long" }

     },

         { "name": "channelId", "type": "long" },

         { "name": "value", "type": "Energistics.Datatypes.DataValue" },

         {

          "name": "valueAttributes",

          "type": { "type": "array", "items": "Energistics.Datatypes.DataAttribute" }

     }

     ]

}

Attribute

Description

Data Type

Min

Max

indexes

The value of the indexes for this data point.

The array MUST be of length 0, or the length of the corresponding index metadata array for the channelId. If the length is 0, then the value is determined from the previous item in the array of DataItem, which MUST have identical index metadata as the channelId of this record.

long

0

n

channelId

The identifier of the channel for this point, as received in a ChannelMetadata record.

long

1

1

value

The value of this data point.

DataValue

1

1

valueAttributes

Any qualifiers, such as quality, accuracy, etc., attached to this data point. Array of ID-value pairs, where the IDs and the values are described as part of this specification. Release 1 of ETP does NOT specify any such value metadata.

DataAttribute

0

n